Which of the following processes includes all others? a. osmosis b. diffusion of a solute across a membrane c. facilitated diffusion d. passive transport e. transport of an ion down its electrochemical gradient

Step 1: Define the Problem

Identify which process encompasses all the others listed in the options.

Step 2: Break Down the Problem

• Osmosis: Movement of water across a semipermeable membrane from low to high solute concentration.
• Diffusion of a solute across a membrane: Movement of solute particles from high to low concentration.
• Facilitated diffusion: Movement of molecules across a membrane via transport proteins, from high to low concentration.
• Passive transport: General term for movement of substances across a membrane without energy input, from high to low concentration.
• Transport of an ion down its electrochemical gradient: Movement of ions influenced by both concentration and electrical gradients.

Step 3: Apply Relevant Concepts

Passive transport is a broad category that includes all types of diffusion (simple, facilitated) and osmosis, as they all involve movement across membranes without energy input.

Step 4: Analysis, Verify and Summarize

• Osmosis is a type of passive transport specific to water.
• Diffusion of a solute across a membrane is a form of passive transport.
• Facilitated diffusion is a type of passive transport involving transport proteins.
• Transport of an ion down its electrochemical gradient is also passive transport.

Final Answer

d. passive transport